Method of evaluating reliable life span of encapsulant film and device for evaluating reliability of said film

ABSTRACT

There are provided a method of evaluating a reliable lifespan of an encapsulant film and a device for evaluating reliability of the film. The present application may provide a film that may be provided for an evaluation method in which reliability of an encapsulant film is simply and easily evaluated only by measuring a haze immediately before the encapsulant film is used, a failure of a product is determined and reliability may be predicted.

This application is a National Stage Entry of International ApplicationNo. PCT/KR2014/005450, filed Jun. 19, 2014, and claims the benefit ofand priority to Korean Application Nos. 10-2013-0070637, filed Jun. 19,2013 and 10-2014-0075206, filed Jun. 19, 2014, all of which are herebyincorporated by reference in their entirety for all purposes as if fullyset forth herein.

TECHNICAL FIELD

The present application relates to a method of evaluating a reliablelifespan of an encapsulant film and a device for evaluating reliabilityof the film.

BACKGROUND OF THE INVENTION

Encapsulant films may be used for protecting elements, devices, and thelike which are sensitive to external factors such as water or oxygen.The elements or devices that may be protected by the encapsulant filminclude, for example, organic electronic devices, solar cells, orrechargeable batteries such as lithium rechargeable batteries. Inparticular, among the elements or the devices, organic electronicdevices are vulnerable to external factors such as water or oxygen.

The organic electronic device is a device including a functional organicmaterial. As the organic electronic device or an organic electronicelement included in the organic electronic device, a photovoltaicdevice, a rectifier, a transmitter, an organic light emitting diode(OLED), and the like may be exemplified.

In general, organic electronic devices are vulnerable to externalfactors such as water. For example, an organic light emitting elementgenerally includes a layer made of a functional organic material that ispresent between a pair of electrodes including a metal or a metal oxide.When water penetrates from the outside, there are problems in that thelayer made of the organic material is exfoliated due to an influence ofmoisture in an interface with the electrode, the electrode is oxidizedby water which results in an increase in a resistance value, and theorganic material itself is degenerated which results in a loss of alight-emitting function or a decrease in brightness.

Accordingly, in order to protect organic light emitting elements fromelements of an external environment such as water, an encapsulationstructure in which an organic light emitting element formed on asubstrate is covered by a glass can or a metal can having a getter or amoisture absorbent provided therein and is fixed with an adhesive, andthe like is used. Also, a method of sealing the organic light emittingelement using an encapsulant film instead of the encapsulation structureis used.

DISCLOSURE Brief Summary of the Invention

The present application relates to a method of evaluating reliability ofan encapsulant film with ease and a device for evaluating reliability ofthe film.

Technical Solution

According to an embodiment of the present application, there is provideda method of evaluating reliability of an encapsulant film. For example,according to the method of the present application, when an organicelectronic device panel is manufactured, since it is possible todetermine availability of a film simply by measuring a haze before theencapsulant film is used, it is possible to provide a film capable ofminimizing a failure rate of an organic electronic device.

DETAILED DESCRIPTION OF THE INVENTION

In the related art, an encapsulation structure in which an organic lightemitting element is covered by a glass can or a metal can having agetter or a moisture absorbent provided therein and is fixed with anadhesive has a problem in that air or oxygen is mixed in a gap formedwhen the organic light emitting element formed on the substrate and theglass can or metal can having a getter or a moisture absorbent providedtherein are separated, which may decrease a lifespan of the organiclight emitting element. Therefore, an encapsulant adhesive film fordirectly covering and sealing the organic light emitting element isused. However, some encapsulant adhesive films have a good adhesionproperty but have a low heat resistant property and water barrierproperty. Accordingly, in order to solve such problems, an encapsulantfilm manufactured by dispersing a moisture absorbent such as a metaloxide having water reactivity to an adhesive film is used. In theencapsulant film containing the moisture absorbent, since the moistureabsorbent chemically absorbs the water that has penetrated into thefilm, it is possible to decrease a rate of water penetration into theorganic light emitting element.

Before the encapsulant film containing an water-reactive moistureabsorbent as described above is applied to the panel in order toencapsulate the organic light emitting element, it is necessary todetermine reliability. This is because, when some moisture absorbent inthe encapsulant film has already reacted with water during a process ofmanufacture, transportation, storage, and the like of the encapsulantfilm, the individual number of the moisture absorbent which may blockwater when the film is applied to the panel decreases and therebyreliability of the encapsulant film decreases.

Before the film is applied to the panel, conventional methods ofevaluating reliability of the water barrier property of the encapsulantfilm containing the moisture absorbent include a weight increase method,a calcium test method, and the like. The weight increase method is basedon a principle that a weight increases while the film reacts with water,but it was inaccurate since a content of a binder resin with respect tothe moisture absorbent and a glass transition temperature are high.Another method, the calcium test method, uses a property in whichcalcium is oxidized by water and becomes transparent. In the calciumtest method, calcium is deposited on a glass, sealed by the encapsulantadhesive film and the glass, and remains under conditions of a relativehumidity of 85% at 85° C. for a predetermined time. Then, a time atwhich calcium becomes transparent is used to evaluate reliability.However, this method consumes time for preparing a sample, and it takes300 hours or more for water to penetrate into calcium in a testspecimen. Therefore, this method is inappropriate as a reliabilityevaluation method of the encapsulant film immediately before the film isapplied to the panel in a production stage.

Therefore, in order to introduce a simpler and more accurate evaluationmethod than the reliability evaluation method of the encapsulant film inthe related art, the inventors devised an evaluation method using hazemeasurement.

As an example, in an evaluation method of the present application, ahaze of a film including a base resin and a moisture absorbent ismeasured within one hour from a time point at which the film is takenout of a water-resistant sealed envelope under conditions of a relativehumidity of 50% at 25° C., and the measured haze value may be used toevaluate a reliable lifespan of the film. Also, in this case, thereliable lifespan of the film may be evaluated as being higher when themeasured haze value of the film is higher.

The haze refers to turbidity (a degree of turbidity) caused by themoisture absorbent included in the film. The haze may be generallymeasured by a haze meter and represented by the following equation. Thehaze may be measured according to, for example, a standard of ASTM D1003.Haze value (%)=(diffuse transmittance (Td)/total light transmittance(Tt))×100

In the above equation, the total light transmittance is a sum of adiffuse transmittance and a parallel transmittance. That is, the diffusetransmittance is obtained by subtracting the parallel transmittance fromthe total light transmittance.

Evaluating reliability of the water barrier property of the encapsulantfilm by measuring only the haze is an accurate evaluation method interms of the following aspects.

First, it was determined that the film manufactured by dispersingfillers having the same size and content under the same conditions has aconstant haze value. Therefore, when the encapsulant film being storedbefore application of film production is a product of the same gradeincluding a moisture absorbent having the same size and content, theevaluation method of the present application may be applied.

Also, when the film is left in wet conditions, a decrease in the hazewas determined. As described above, due to a hydration reaction of themoisture absorbent included in the encapsulant film with water thatpenetrates into the film, a hydrate, which is an aggregate of metaloxides, is generated from an outermost portion of the moistureabsorbent, downsizing of an effective moisture absorbent that may reactwith water may be caused and thereby the haze decreases. Also, when arefractive index of the moisture absorbent is changed by the hydrationreaction, the refractive index matches an organic binder and the hazedecreases. Accordingly, in order to apply the encapsulant film beingstored to the panel, it is necessary to secure the individual number ofeffective moisture absorbent which may react with water to apredetermined level or more, which means that the haze needs to bemaintained to a predetermined level or more.

Finally, it was determined that there is a correlation between adecrease in the haze and a decrease in the water barrier property, thatis, a lifespan of the encapsulant film. Films having the same grade andhaving the same moisture absorbent dispersed thereon were left under thesame conditions for a predetermined time, and the haze and the waterpenetration distance were simultaneously measured to determine the waterbarrier property. As a result, it was determined that the waterpenetration distance becomes longer in the test specimen as the hazedecreases. Therefore, it may be understood that a correlation between adecrease in the haze and the lifespan of the film resulting from thewater barrier property is established.

Therefore, unlike the conventional evaluation method, it is possible toevaluate reliability of the lifespan of the encapsulant film simply bymeasuring the haze. Since this method does not require a long time as inthe calcium test method and has no influence from the binder resin orother components as in the weight increase method, it is an accurateevaluation method.

In an example, the haze value of the film measured by the above methodmay satisfy the following General Equation 1.

$\begin{matrix}{{Hz} = {{- m}\;{\mathbb{e}}^{{- \phi}\;{{hr}{({{n_{g}/n} - 1})}}^{2}}}} & \left\lbrack {{General}\mspace{14mu}{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In General Equation 1, Hz represents a haze value (%) of the film thatis measured within one hour from a time point at which the film is takenout of the water-resistant sealed envelope under conditions of arelative humidity of 50% at 25° C. using the haze meter, m represents avalue greater than 0, Φ represents a content of the moisture absorbentwith respect to the base resin, h represents a thickness of the film, rrepresents an average particle diameter of the moisture absorbent, n_(g)represents a refractive index of the moisture absorbent, and nrepresents a refractive index of the base resin.

For example, the haze value of the film may be a value that is changedby the content of the moisture absorbent, the thickness of the film, theaverage particle diameter of the moisture absorbent, the refractiveindex of the moisture absorbent, and the refractive index of the baseresin, which may satisfy the above relation. Therefore, in the method ofthe present application, it is possible to evaluate reliabilityaccording to an absolute value of the haze and evaluate reliabilityaccording to various haze values in consideration of the parameters. Forexample, as described above, a haze of 10 is not unconditionallyevaluated as having a shorter reliable lifespan than a haze of 20. Sinceevaluation may be performed in consideration of the parameters inGeneral Equation 1, it is possible to evaluate the reliable lifespanmore accurately.

FIG. 1 is a graph showing a relation between a content of the moistureabsorbent and the haze.

As shown in FIG. 1, a value of the haze gradually increases as thecontent of the moisture absorbent increases. Therefore, the content ofthe moisture absorbent may be a main factor for determining the value ofthe haze.

Also, in the method of the present application, the measured haze valueof the film may satisfy the following General Equation 2.D=k/Hz  [General Equation 2]

In General Equation 2, Hz represents a haze value (%) of the film thatis measured within one hour from a time point at which the film is takenout of the water-resistant sealed envelope under conditions of arelative humidity of 50% at 25° C. using the haze meter, D represents awater penetration distance (mm) of the film that is measured after thefilm of which a haze is measured is laminated between two glasssubstrates and maintained under conditions of a temperature of 85° C.and a relative humidity of 85% for 0 to 1500 hours, and k represents avalue equal to or greater than one as a proportional constant.

In the above description, the water penetration distance represents alength or a distance to which water penetrates from an outermost edge ofthe film toward a center of the film after the film of which a haze ismeasured is laminated between two glass substrates and maintained underconditions of a temperature of 85° C. and a relative humidity of 85% for0 to 1500 hours. For example, a ruler, a vernier caliper, an opticalmicroscope, and the like may be used to measure, but a measurementdevice is not limited thereto.

In the evaluation method of the present application, the measured hazevalue of the film satisfies General Equation 2 and a relation betweenthe measured haze value of the film and the water penetration distancemay be inversely proportional. For example, as the haze value of thefilm increases, the water penetration distance of the film may decrease.That is, in the method of the present application, it is possible toevaluate the reliable lifespan of the film simply by measuring the hazeusing the fact that water does not easily penetrate into the film when ahigher haze value of the film is measured.

FIGS. 2 to 5 are graphs showing the relation between the waterpenetration distance and the haze which were measured after the films ofthe present application were maintained under conditions of atemperature of 85° C. and a relative humidity of 85% for 100 hours, 300hours, 500 hours, and 1000 hours, respectively.

As shown in FIGS. 2 to 5, it may be seen that there is a constantrelation between the haze and the water penetration distance. Inparticular, it may be seen that the water penetration distance decreasesas the haze value increases.

The evaluation method may be performed by comparing haze values of twoor more films. In this case, the evaluation method may be applied to thehaze values measured from the encapsulant films including the moistureabsorbent having the same size and type under the same conditions. Forexample, measurement of the water penetration distance of the two ormore films may be performed after specimens are manufactured while theencapsulant films are interposed between glasses and left in a relativehumidity of 85% at 85° C. for 0 to 1500 hours. In this case, it ispreferred that a time for which the specimens are maintained in theseconditions is the same time from 0 to 1500 hours.

Another embodiment of the present application relates to a device formeasuring reliability of a film used in the evaluation method.

FIG. 6 is a diagram schematically illustrating an exemplary measuringdevice.

As illustrated in FIG. 6, the reliability measuring device of thepresent application includes a light source 11, an integrating sphere12, and a measuring unit 13.

The light source 11 is included in the measuring device of the presentapplication in order to radiate light to a sample film. The light source11 radiates light necessary for measuring the haze of the sample film,and the light source 11 used in a general haze measuring device may beused for the measuring device of the present application.

The integrating sphere 12 is a member configured to detect lightpenetrating the sample film and measure the haze. The integrating sphere12 is formed such that light passing through the sample film isincident, and the integrating sphere 12 used in the general hazemeasuring device may be used for the measuring device of the presentapplication. The integrating sphere 12 measures the haze by detectingtotal transmitted light and scattered light of light incident throughthe sample film. In this case, the integrating sphere 12 may calculatethe diffuse transmittance (Td) and the total light transmittance (Tt) bydetecting diffused light and total transmitted light.

The measuring unit 13 is a member configured to measure reliability ofthe film using the haze value measured by the integrating sphere 12, forexample, may be a calculating device having an algorithm that evaluatesthe reliable lifespan as being longer when the haze value is higher.

In an example, the measuring unit 13 may include an input unitconfigured to receive the haze value of the film measured by theintegrating sphere 12, an evaluation unit configured to evaluatereliability of the film based on the received haze value, and a displayunit configured to display the evaluation result.

For example, the haze value measured by the integrating sphere 12 may beinput to the input unit through an electrical signal. Also, at least oneselected from the group consisting of the content of the moistureabsorbent in the sample film, the average particle diameter of themoisture absorbent, the refractive index of the moisture absorbent, thethickness of the sample film, and the refractive index of the base resinin the sample film may be additionally input to the input unit.

After the reliable lifespan is evaluated based on the input haze valueand the additionally input values, the evaluation unit delivers theevaluation result to the display unit.

In an example, the evaluation unit may have an algorithm that evaluatesthe reliable lifespan as being higher when the haze value is higher.

For example, in order to evaluate reliability according to the absolutevalue of the haze, the evaluation unit may include a first algorithm inwhich the absolute value of the haze measured within one hour from atime point at which the sample film is taken out of the water-resistantsealed envelope under conditions of a relative humidity of 50% at 25° C.is graded and a grade of the lifespan is classified based thereon. Whenthe evaluation unit evaluates the reliable lifespan of the filmaccording to the first algorithm, the absolute value of the haze valueof the sample film is simply used as a reference and the grade of thereliable lifespan may be evaluated based on the absolute value.

In another embodiment of the evaluation unit, the evaluation unit mayinclude a second algorithm that may evaluate the absolute value of thehaze in consideration of other parameters influencing the haze value,for example, the content of the moisture absorbent in the sample film,the average particle diameter of the moisture absorbent, the refractiveindex of the moisture absorbent, the thickness of the sample film or therefractive index of the base resin in the sample film, which areadditionally input to the input unit. For example, in the secondalgorithm, m may be calculated by the following General Equation 1.

$\begin{matrix}{{Hz} = {{- m}\;{\mathbb{e}}^{{- \phi}\;{{hr}{({{n_{g}/n} - 1})}}^{2}}}} & \left\lbrack {{General}\mspace{14mu}{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In General Equation 1, Hz represents a haze value (%) of the film thatis measured within one hour from a time point at which the film is takenout of the water-resistant sealed envelope under conditions of arelative humidity of 50% at 25° C. using the haze meter, m represents avalue greater than 0, Φ represents a content of the moisture absorbentwith respect to the base resin, h represents a thickness of the film, rrepresents an average particle diameter of the moisture absorbent, n_(g)represents a refractive index of the moisture absorbent, and nrepresents a refractive index of the base resin.

As described above, the haze value of the film may be a value that ischanged by the content of the moisture absorbent, the thickness of thefilm, the average particle diameter of the moisture absorbent, therefractive index of the moisture absorbent, and the refractive index ofthe base resin, which may satisfy the above relation. Therefore, in theevaluation unit of the measuring device of the present application,reliability may be evaluated by the absolute value of the haze by thefirst algorithm, and reliability may be evaluated by various haze valuesin consideration of the parameters by the second algorithm. For example,as described above, a haze of 10 is not unconditionally evaluated ashaving a shorter reliable lifespan than a haze of 20. Since evaluationmay be performed in consideration of the parameters in General Equation1, it is possible to evaluate the reliable lifespan more accurately.

The display unit may display a display result received from theevaluation unit and may use, for example, various display devices knownin the art.

According to still another embodiment of the present application, thereis provided a film, and specifically, an encapsulant film forencapsulating an organic light emitting element of an organic electronicdevice. The encapsulant film of the present application includes themoisture absorbent to exhibit a haze decrease property caused by areaction of the moisture absorbent with water. Therefore, reliability ofthe film may be evaluated by measuring the haze of the encapsulant filmincluding the moisture absorbent. When the organic electronic devicepanel is manufactured, since it is possible to determine availability ofthe film simply by measuring the haze before the encapsulant film isused, it is possible to provide the film capable of minimizing a failurerate of the organic electronic device.

In an embodiment of the present application, the film may satisfy thefollowing General Equation 1.

$\begin{matrix}{{Hz} = {{- m}\;{\mathbb{e}}^{{- \phi}\;{{hr}{({{n_{g}/n} - 1})}}^{2}}}} & \left\lbrack {{General}\mspace{14mu}{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In General Equation 1, Hz represents a haze value (%) of the film thatis measured within one hour from a time point at which the film is takenout of the water-resistant sealed envelope under conditions of arelative humidity of 50% at 25° C. using the haze meter, m represents avalue greater than 0, Φ represents a content of the moisture absorbentwith respect to the base resin, h represents a thickness of the film, rrepresents an average particle diameter of the moisture absorbent, n_(g)represents a refractive index of the moisture absorbent, and nrepresents a refractive index of the base resin.

As described above, the haze value of the film may be a value that ischanged by the content of the moisture absorbent, the thickness of thefilm, the average particle diameter of the moisture absorbent, therefractive index of the moisture absorbent, and the refractive index ofthe base resin, which may satisfy the above relation. Therefore, whenreliability of the film is evaluated by measuring the haze of theencapsulant film using a haze decrease property caused by a reaction ofthe moisture absorbent of the film with water, it is possible toevaluate reliability according to the absolute value of the haze andalso evaluate reliability according to various haze values inconsideration of the parameters. For example, a haze of 10 is notunconditionally evaluated as having a shorter reliable lifespan than ahaze of 20. Since evaluation may be performed in consideration of theparameters in General Equation 1, it is possible to evaluate thereliable lifespan more accurately.

In still another embodiment of the present application, the filmsatisfies the following General Equation 2.D=k/Hz  [General Equation 2]

In General Equation 2, Hz represents a haze value (%) of the film thatis measured within one hour from a time point at which the film is takenout of the water-resistant sealed envelope under conditions of arelative humidity of 50% at 25° C. using the haze meter, D represents awater penetration distance (mm) of the film that is measured after thefilm of which a haze is measured is laminated between two glasssubstrates and maintained under conditions of a temperature of 85° C.and a relative humidity of 85% for 0 to 1500 hours, and k represents avalue equal to or greater than one as a proportional constant.

In an example, in the film of the present application satisfying GeneralEquation 2, a relation between the measured haze value of the film andthe water penetration distance may be inversely proportional. Forexample, as the haze value of the film increases, the water penetrationdistance of the film may decrease. That is, when a higher haze value ofthe film according to the present application is measured, water doesnot easily penetrate into the film. Accordingly, evaluation of thereliable lifespan of the film, which will be described below, may beperformed simply by measuring the haze.

In another embodiment of the present application, the film of thepresent application may satisfy the following General Equation 3.D=−α×Hz+β  [General Equation 3]

In General Equation 3, Hz represents a haze value (%) of the film thatis measured within one hour from a time point at which the film is takenout of the water-resistant sealed envelope under conditions of arelative humidity of 50% at 25° C. using the haze meter, D represents awater penetration distance (mm) of the film that is measured after thefilm is laminated between two glass substrates and maintained underconditions of a temperature of 85° C. and a relative humidity of 85% for0 to 1500 hours, α is 0.01 or more, and β is 1.0 or more and is greaterthan D.

The film of the present application may satisfy a relation between thehaze and the water penetration distance defined in General Equation 3.For example, measured values of the haze and the water penetrationdistance of the film of the present application may be present in anarea in which a straight line of General Equation 3 may be drawn.Accordingly, as described above, it is possible to evaluate the reliablelifespan of the film simply by measuring the haze.

α represents a slope of a straight line represented by General Equation3, and may be 0.01 or more, for example, 0.015 or more, 0.02 or more,0.025 or more, 0.03 or more, 0.035 or more, 0.04 or more, or 0.045 ormore, but the value is not limited thereto. The slope may increase as atime for which the film is exposed to water increases when the waterpenetration distance of the film is measured. An upper limit of theslope is not specifically limited, but may be adjusted in a range inwhich an x axis representing the haze value and the straight line inGeneral Equation 3 are not perpendicular, and may be, for example, 0.9or less, 0.8 or less, 0.7 or less, 0.5 or less, 0.4 or less, 0.3 orless, 0.2 or less, or 0.1 or less.

β represents a y-intercept of the straight line represented by GeneralEquation 3, and may be 1.0 or more, 2.0 or more, 3.0 or more, 4.0 ormore, 5.0 or more, 6.0 or more, 7.0 or more, or 8.0 or more, but thevalue is not limited thereto. A value of the y-intercept may alsoincrease as a time for which the film is exposed to water increases whenthe water penetration distance of the film is measured. An upper limitof the y-intercept is not specifically limited, but may be 15 or less,14 or less, 13 or less, 12 or less, 11 or less or 10 or less.

As shown in FIGS. 2 to 5, it may be seen that there is a constantrelation between the haze and the water penetration distance. Inparticular, it may be seen that the water penetration distance decreasesas the haze value increases. Also, it may be seen that the slope and they-intercept in General Equation 3 increase when a time for which thefilm is exposed to a humidity condition increases.

In an exemplary film of the present application, conditions of GeneralEquation 1 and/or General Equation 2 may be satisfied for theencapsulant film for encapsulating an organic electronic device havingthe same bezel size. For example, when a bezel size of the organicelectronic device is fixed at any value in a range of 2 mm to 20 mm, theencapsulant film in the organic electronic device may satisfy thefollowing General Equation 1 and/or General Equation 2.

Also, conditions of General Equation 1 and/or General Equation 2 may besatisfied in one film or two or more films including moisture absorbenthaving the same conditions, for example, the moisture absorbent of thesame type, the same content and/or the same average particle diameter,but the present invention is not limited thereto.

The film of the present application satisfying General Equation 2 and/orGeneral Equation 3 includes the base resin and the moisture absorbent.For example, when the film of the present application including the baseresin and the moisture absorbent is left in wet conditions, the haze maydecrease, and thereby General Equation 1 and/or 2 may be satisfied. Thatis, due to a hydration reaction of the moisture absorbent included inthe film with water penetrated into the film, a hydrate, which is anaggregate of metal oxides, is generated from an outermost portion of themoisture absorbent, and downsizing of an effective moisture absorbentaggregate that may react with water may be caused and thereby the hazemay decrease. Also, due to a change in a refractive index of themoisture absorbent caused by the hydration reaction, the refractiveindex matches an organic binder and the haze decreases. Accordingly, inorder to apply the encapsulant film being stored to the panel, it isnecessary to secure the number of effective particles of the moistureabsorbent which may react with water to a predetermined level or more,which means that the haze needs to be maintained in a predeterminedlevel or more.

In another embodiment of the present application, the haze of theencapsulant film may satisfy the following General Equation 4.Hz≧30%  [General Equation 4]

In General Equation 4, Hz represents a haze of the film measured usingthe haze meter. The haze value is not specifically limited, but may be avalue measured with respect to, for example, a film having a thicknessof 30 μm or 40 μm.

The haze may be 30% or more, for example, 40% or more or 50% or more. Inorder to suppress damage of the organic electronic element, the hazevalue of the film is adjusted in the above range according to a lengthof the bezel of the organic electronic device so that the lifespan ofthe organic electronic device is secured. In this case, since themoisture absorbent has a light scattering characteristic, it may beappropriately particularly applied to an organic electronic device of abottom emission type.

Also, the haze may be a value measured from, for example, a film havinga water penetration distance D of less than 10 mm. When the hazesatisfies the above range in a water penetration distance of less than10 mm, a correlation having high reliability between the haze and thewater penetration distance of General Equation 1 and/or General Equation2 may be derived.

In an example, the film may be a curable hot melt type adhesive film.The term “hot melt type adhesive film” used in this specification mayrefer to a film that maintains a solid or semi-solid state at roomtemperature, melts and exhibits adhesiveness when appropriate heat isapplied, and is able to firmly fix a subject material as an adhesiveafter curing. Also, the term “curing of the adhesive” in thisspecification may refer to a chemical or physical action or reactionwhich enables the subject material to be changed to exhibit an adhesiveproperty. Also, the term “room temperature” refers to a naturaltemperature without heating or cooling, and may refer to a temperatureof, for example, about 15° C. to 35° C., about 20° C. to 25° C., orabout 25° C. or 23° C. Also, in the above description, maintaining thesolid or semi-solid state at room temperature may refer to the fact thatthe subject material exhibits a viscosity of about 10⁶ poise or more, orabout 10⁷ poise or more at room temperature. In the above description,the viscosity is measured using an advanced rheometric expansion system(ARES). In the above description, an upper limit of the viscosity is notspecifically limited, and may be, for example, about 10⁹ poise or less.

For example, when contained components are not cured, the film maymaintain a solid or semi-solid state at room temperature. That is, acurable resin composition may be included in the form of a film.Therefore, it is possible to provide a film that is easy to handle,prevents physical or chemical damage of elements in application of anencapsulation process and the like, and can be processed smoothly.

In an example, a water vapor transmission rate (WVTR) of the film may be50 g/m²·day or less or 30 g/m²·day or less. The WVTR may be a WVTRmeasured with respect to a film having a thickness of 100 μm under arelative humidity of 100% at 100° C. in a thickness direction of thefilm. The WVTR of the film is controlled as described above so that afilm exhibiting an excellent water barrier property may be provided. Thelower WVTR may indicate a more excellent water barrier property, and alower limit thereof is not specifically limited. A lower limit of theWVTR of the film may be, for example, 0 g/m²·day.

In the embodiments of the present application, as the base resinincluded in the encapsulant film, a thermoplastic resin or an elastomermay be used, or a curable resin may be used without limitation.

In an example, examples of the thermoplastic resin or the elastomer, andthe curable resin may include a styrene-based resin or elastomer, apolyolefin-based resin or elastomer, other elastomers, apolyoxyalkylene-based resin or elastomer, a polyester-based resin orelastomer, a polyvinyl-chloride-based resin or elastomer, apolycarbonate-based resin or elastomer, a polyphenylene-sulfide-basedresin or elastomer, mixtures of hydrocarbons, a polyamide-based resin orelastomer, an acrylate-based resin or elastomer, an epoxy-based resin, asilicone-based resin or elastomer, a fluorine-based resin or elastomer,or mixtures thereof.

In the above description, examples of the styrene-based resin orelastomer may include a styrene-ethylene-butadiene-styrene blockcopolymer (SEBS), a styrene-isoprene-styrene block copolymer (SIS), anacrylonitrile-butadiene-styrene block copolymer (ABS), anacrylonitrile-styrene-acrylate block copolymer (ASA), astyrene-butadiene-styrene block copolymer (SBS), a styrene-basedhomopolymer, or mixtures thereof. Examples of the olefin-based resin orelastomer may include a high-density polyethylene-based resin orelastomer, a low-density polyethylene-based resin or elastomer, apolypropylene-based resin or elastomer, or mixtures thereof. Examples ofthe elastomer may include an ester-based thermoplastic elastomer, anolefin-based elastomer, a silicone-based elastomer, an acrylic-basedelastomer, or mixtures thereof. Among these, as the olefin-basedthermoplastic elastomer, a polybutadiene resin or elastomer, apolyisobutylene resin or elastomer, and the like may be used. Examplesof the polyoxyalkylene-based resin or elastomer may include apolyoxymethylene-based resin or elastomer, a polyoxyethylene-based resinor elastomer, or mixtures thereof. Examples of the polyester-based resinor elastomer may include a polyethyleneterephthalate-based resin orelastomer, a polybutyleneterephthalate-based resin or elastomer, ormixtures thereof. Examples of the polyvinyl chloride-based resin orelastomer may include polyvinylidene chloride and the like. Examples ofthe mixtures of hydrocarbons may include hexatriacotane, paraffin, andthe like. Examples of the polyamide-based resin or elastomer may includenylon and the like. Examples of the acrylate-based resin or elastomermay include polybutyl(meth)acrylate and the like. Examples of theepoxy-based resin may include a bisphenol type such as a bisphenol Atype, a bisphenol F type, a bisphenol S type and water-added materialsthereof; a novolac type such as a phenol novolac type and a cresolnovolac type; a nitrogen-containing ring type such as a triglycidylisocyanurate type and a hydantoin type; an alicyclic type; an aliphatictype; a naphthalene type, an aromatic type such as a biphenyl type; aglycidyl type such as a glycidyl ether type, a glycidylamine type, and aglycidyl ester type; a dicyclo type such as a dicyclopentadiene type; anester type; an etherester type, or mixtures thereof. Examples of thesilicone-based resin or elastomer may include polydimethylsiloxane andthe like. Also, examples of the fluorine-based resin or elastomer mayinclude a polytrifluoroethylene resin or elastomer, apolytetrafluoroethylene resin or elastomer, apolychlorotrifluoroethylene resin or elastomer, apolyhexafluoropropylene resin or elastomer, polyvinylidene fluoride,polyvinyl fluoride, poly(fluorinated ethylene-propylene), or mixturesthereof.

When the listed resins or elastomers are used, they may be grafted with,for example, maleic anhydride and the like, may be copolymerized withother listed resins or elastomers, or monomers for preparing resins orelastomers, or may be denaturalized by other compounds. Examples of theother compounds may include a carboxyl-terminatedbutadiene-acrylonitrile copolymer and the like.

In an embodiment of the present application, the base resin may be athermoplastic elastomer or a thermoplastic resin.

Examples of the thermoplastic resin or elastomer may include astyrene-based resin or elastomer, a polyolefin-based resin or elastomer,other elastomers, a polyoxyalkylene-based resin or elastomer, apolyester-based resin or elastomer, a polyvinyl-chloride-based resin orelastomer, a polycarbonate-based resin or elastomer, apolyphenylene-sulfide-based resin or elastomer, mixtures ofhydrocarbons, a polyamide-based resin or elastomer, an acrylate-basedresin or elastomer, a silicone-based resin or elastomer, afluorine-based resin or elastomer, or mixtures thereof.

In an example, the thermoplastic resin may be a copolymer ofolefin-based compounds having a carbon-carbon double bond, but the resinis not limited thereto.

Also, the base resin may be a copolymer of diene and an olefin-basedcompound having a single carbon-carbon double bond. Here, theolefin-based compound may include isobutylene, propylene, ethylene, andthe like. The diene may be a monomer that may be polymerized with theolefin-based compound, and may include, for example, 1-butene, 2-butene,isoprene, or butadiene. That is, as the base resin, for example, ahomopolymer of an isobutylene monomer; a copolymer obtained bycopolymerizing the isobutylene monomer with other polymerizablemonomers; or mixtures thereof may be used. In an example, the copolymerof the olefin-based compound having a single carbon-carbon double bondand the diene may be butyl rubber.

The thermoplastic elastomer base resin may have a weight-averagemolecular weight (Mw) at which molding in the form of a film ispossible. For example, the resin may have a weight-average molecularweight of about 100,000 to 2,000,000, 100,000 to 1,500,000, or 100,000to 1,000,000. The term “weight-average molecular weight” in thisspecification refers to a conversion value with respect to a standardpolystyrene measured using gel permeation chromatography (GPC). However,the thermoplastic resin or elastomer component does not necessarily havethe above-mentioned weight-average molecular weight. For example, when amolecular weight of the thermoplastic resin or elastomer component doesnot reach a level at which the film can be formed, a separate binderresin may be mixed as a component forming the encapsulant film.

In another embodiment, the base resin may be a curable resin. A detailedtype of the curable resin that may be used in the present application isnot specifically limited. For example, various thermosetting orphotocurable resins known in the related art may be used. In the abovedescription, the term “thermosetting resin” refers to a resin that maybe cured by applying appropriate heat or an aging process, and the term“photocurable resin” refers to a resin that may be cured by radiation ofelectromagnetic waves. Also, in the above description, a category of theelectromagnetic waves may include microwaves, infrared (IR), ultraviolet(UV), X-rays, and γ-rays, and further include particle beams such as anα-particle beam, a proton beam, a neutron beam, and an electron beam. Inthe present application, an example of a photocurable type resin mayinclude a cationic photocurable type resin. The cationic photocurabletype resin refers to a resin that may be cured by a cationicpolymerization or cationic curing reaction derived by radiation ofelectromagnetic waves. Also, the curable resin may be a dual curabletype resin having thermosetting and photocurable properties.

As the curable resin, for example, as a resin that may exhibit anadhesive property by curing, a resin having at least one functionalgroup or part that may be cured by heat such as a glycidyl group, anisocyanate group, a hydroxyl group, a carboxyl group, or an amide groupmay be used, and a resin having at least one functional group or partthat may be cured by radiation of active energy rays such as an epoxidegroup, a cyclic ether group, a sulfide group, an acetal group, or alactone group may be used. Examples of the curable resin may include apolyolefin resin, an acryl resin, a polyester resin, an isocyanateresin, or an epoxy resin which has at least one functional group or partdescribed above, but the curable resin is not limited thereto.

In an example, as the curable resin, the epoxy resin may be used. Theepoxy resin may be an aromatic-based or aliphatic-based epoxy resin. Asthe epoxy resin, a thermosetting epoxy resin may be used or an activeenergy ray curable resin, for example, an epoxy resin that is cured by acationic polymerization reaction due to radiation of active energy rays,may be used.

The epoxy resin according to the example may have an epoxide equivalentweight of 150 g/eq to 2,000 g/eq. At epoxide equivalent weights withinthis range, properties of a cured product such as adhesive performanceor a glass transition temperature may be maintained in an appropriaterange. Examples of the epoxy resin may include a cresol novolac epoxyresin, a bisphenol A type epoxy resin, a bisphenol A type novolac epoxyresin, a phenol novolac epoxy resin, a tetrafunctional epoxy resin, abiphenyl type epoxy resin, a triphenylmethane type epoxy resin, analkyl-modified triphenylmethane epoxy resin, a naphthalene type epoxyresin, a dicyclopentadiene type epoxy resin, or adicyclopentadiene-modified phenol type epoxy resin, and mixtures ofthereof.

In the present application, an epoxy resin having a cyclic structure inits molecular structure may be preferably used. In an example, the epoxyresin may be an aromatic-based epoxy resin. The term “aromatic-basedepoxy resin” in this specification may refer to an epoxy resin having atleast one of an aromatic core such as a phenylene structure or anaromatic group such as a phenyl group at a main chain or side chain ofthe resin. When the aromatic-based epoxy resin is used, the curedproduct has excellent thermal and chemical stability and a low moisturepermeation degree so that reliability of an electronic deviceencapsulation structure may increase. Examples of the aromatic-basedepoxy resin may include a biphenyl type epoxy resin, a naphthalene typeepoxy resin, a dicyclopentadiene type epoxy resin, adicyclopentadiene-modified phenol type epoxy resin, a cresol-based epoxyresin, a bisphenol-based epoxy resin, a xylok-based epoxy resin, amultifunctional epoxy resin, a phenol novolac epoxy resin, atriphenolmethane type epoxy resin, an alkyl-modified triphenolmethaneepoxy resin, or mixtures thereof, but the aromatic-based epoxy resin isnot limited thereto.

In an example, the epoxy resin may be a silane-modified epoxy resin. Asthe silane-modified epoxy resin, for example, a reactant of a silanecompound and at least one epoxy resin among the above-described epoxyresins may be used. In this manner, when an epoxy resin that has beenmodified to silane and structurally has a silane group is used, anadhesive property with a glass substrate, a substrate inorganicmaterial, and the like of the organic electronic device may bemaximized, and a water barrier property, durability, reliability, andthe like may increase. A detailed type of the epoxy resin that may beused in the present application is not specifically limited. Such aresin may be easily obtained from a supplier, for example, KukdoChemical Co., Ltd.

In the above description, as the silane compound, for example, acompound represented by the following Chemical Formula 1 may beexemplified.D_(n)SiQ_((4−n))  [Chemical Formula 1]

In Chemical Formula 1, D represents an a vinyl group, an epoxy group, anamino group, an acryl group, a methacrylic group, a mercapto group, analkoxy group, or an isocyanate group, or an alkyl group substituted withany functional group among these, Q represents hydrogen, an alkyl group,a halogen, an alkoxy group, an aryl group, an aryloxy group, an acyloxygroup, an alkylthio group, or an alkyleneoxythio group, and n is 1 to 3.

In a compound in Chemical Formula 1, the functional group D may reactwith a functional group included in the epoxy resin and form thesilane-modified epoxy resin.

When the functional group is, for example, the amino group, the aminogroup may react with an epoxy group of the epoxy resin, form a bond of“—CH(OH)—CH₂—NH—,” and the silane compound may be introduced into theepoxy group.

Also, when the functional group D is the isocyanate group or the alkoxygroup, the silane compound may be introduced by reacting with an epoxyresin containing a hydroxyl group (OH), for example, a bisphenol typeepoxy resin such as a bisphenol F type epoxy resin, a bisphenol F typenovolac epoxy resin, a bisphenol A type epoxy resin, or a bisphenol Atype novolac epoxy resin.

In Chemical Formula 1, as the alkyl group, an alkyl group having 1 to 20carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbonatoms, or 1 to 4 carbon atoms may be exemplified. The alkyl group may bea straight chain, branched, or cyclic type alkyl group.

In Chemical Formula 1, as a halogen atom, fluorine (F), chlorine (Cl),bromine (Br), iodine (I), and the like may be exemplified.

Also, in Chemical Formula 1, as the alkoxy group, an alkoxy group having1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to4 carbon atoms may be exemplified. The alkoxy group may be a straightchain, branched, or cyclic type.

Also, in Chemical Formula 1, as the aryl group or as the aryl groupincluded in the aryloxy group, in addition to the aryl group, an aralkylgroup and the like may be included. For example, the aryl group mayrefer to a compound having at least one benzene ring or a structure inwhich two or more benzene rings are connected or condensed or amonovalent residue derived from a derivative thereof. The aryl group maybe, for example, an aryl group having 6 to 25 carbon atoms, 6 to 21carbon atoms, 6 to 18 carbon atoms, or 6 to 12 carbon atoms. Examples ofthe aryl group may include a phenyl group, a dichlorophenyl group, achlorophenyl group, a phenylethyl group, a phenylpropyl group, a benzylgroup, a tolyl group, a xylyl group, or a naphthyl group.

Also, in Chemical Formula 1, as the acyloxy group, an acyloxy grouphaving 1 to 20 carbon atoms, 1 to 16 carbon atoms, or 1 to 12 carbonatoms may be exemplified.

Also, in Chemical Formula 1, as the alkylthio group, an alkylthio grouphaving 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms,1 to 8 carbon atoms, or 1 to 4 carbon atoms may be exemplified. As thealkyleneoxythio group, an alkyleneoxythio group having 1 to 20 carbonatoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms,or 1 to 4 carbon atoms may be exemplified.

The alkyl group, the alkoxy group, the aryl group, the acyloxy group,the alkylthio group, or the alkyleneoxythio group may be arbitrarilysubstituted with at least one substituent. Examples of the substituentmay include a hydroxyl group, an epoxy group, an alkyl group, an alkenylgroup, an alkynyl group, an alkoxy group, an acyl group, a thiol group,an acryloyl group, a methacryloyl group, an aryl group, or an isocyanategroup, but the substituent is not limited thereto.

In Chemical Formula 1, the functional group D may be, for example, thealkoxy group, the amino group, or the isocyanate group among them.

Also, in Chemical Formula 1, at least one, two or more, or three of thefunctional group Q may be, for example, a halogen atom, the alkoxygroup, the aryloxy group, the acyloxy group, the alkylthio group, thealkyleneoxythio group, or the alkoxy group.

As the silane-modified epoxy resin, for example, an epoxy resin in whicha silane compound of about 0.1 parts by weight to about 10 parts byweight, about 0.1 parts by weight to about 9 parts by weight, about 0.1parts by weight to about 8 parts by weight, about 0.1 parts by weight toabout 7 parts by weight, about 0.1 parts by weight to about 6 parts byweight, about 0.1 parts by weight to about 5 parts by weight, about 0.1parts by weight to about 4 parts by weight, about 0.1 parts by weight toabout 3 parts by weight, about 0.3 parts by weight to 2 parts by weight,or about 0.5 parts by weight to about 2 parts by weight is introducedwith respect to 100 parts by weight of the epoxy resin may be used. Inan example, the epoxy resin into which the silane compound is introducedmay be the aromatic-based epoxy resin. Examples of the aromatic-basedepoxy resin may a bisphenol type epoxy resin such as a bisphenol F typeepoxy resin, a bisphenol F type novolac epoxy resin, a bisphenol A typeepoxy resin, or a bisphenol A type novolac epoxy resin.

When the base resin is the curable resin, the encapsulant film mayadditionally include an epoxy curable binder resin. When a curing baseresin is molded in the form of a film or a sheet, the epoxy curablebinder resin may improve moldability.

A type of the epoxy curable binder resin is not specifically limited, aslong as it has compatibility with other resins such as a curable resin.As the epoxy curable binder resin, a phenoxy resin, an acrylate resin,or a high molecular weight epoxy resin may be used. In the abovedescription, the high molecular weight epoxy resin may refer to, forexample, a resin having a weight-average molecular weight of about 2,000to 6,000. As the high molecular weight epoxy resin, a solid typebisphenol A type epoxy resin, a solid type bisphenol F type epoxy resin,and the like may be exemplified. As the epoxy curable binder resin, arubber component such as high polarity functional group-containingrubber or high polarity functional group-containing reactive rubber maybe used. In an example, as the epoxy curable binder resin, the phenoxyresin may be used.

In embodiments of the present application, the encapsulant filmencapsulating the organic electronic element may have a multi-layerstructure including a first layer that comes in contact with the organicelectronic device and a second layer that does not come in contact withthe organic electronic device when the encapsulant film encapsulates theorganic electronic device. Here, the multi-layer structure does notnecessarily mean a two-layer structure but may include a structurehaving two or more layers depending on characteristics required formanufacturing the panel.

Depending on characteristics and economical feasibility of the panel,both of the first layer and the second layer may be made of a curingbase resin or a thermoplastic elastomer base resin. Also, themulti-layer structure may be formed by mixing a layer made of the curingbase resin and a layer made of the thermoplastic elastomer base resin.In an example, the first layer and second layer may include any oneresin of the polyolefin-based resin and the epoxy-based resin. Forexample, the multi-layer structure may include a structure in which thefirst layer is made of the polyolefin-based resin and the second layeris made of the epoxy-based resin; a structure in which both of the firstlayer and the second layer are made of the polyolefin-based resin; astructure in which the first layer is made of the epoxy-based resin andthe second layer is made of the polyolefin-based resin; and a structurein which both of the first layer and the second layer are made of theepoxy-based resin.

In embodiments of the present application, the encapsulant film includesthe moisture absorbent. The term “moisture absorbent” in thisspecification may refer to, for example, a material that may absorbwater by a chemical reaction with water or moisture that has penetratedinto the encapsulant film.

In an example, the moisture absorbent may include a water reactiveadsorbent, a physical adsorbent, or mixtures thereof. The water reactiveadsorbent may absorb water or moisture by chemically reacting withmoisture, water, oxygen, and the like introduced into the encapsulantfilm. The physical adsorbent may suppress penetration of water ormoisture by making a flowing path of water or moisture penetrating intoan encapsulation structure longer, and may maximize a barrier propertyagainst water and moisture through a matrix structure of the base resinand an interaction with the water reactive adsorbent, and the like.

A detailed type of the moisture absorbent that may be used in thepresent application is not specifically limited. The water reactiveadsorbent may include, for example, a metal powder such as alumina, ametal oxide, a metal salt, phosphorus pentoxide (P₂O₅), or a mixturethereof. The physical adsorbent may include silica, zeolite, titania,zirconia, montmorillonite, and the like.

In the above description, specific examples of the metal oxide mayinclude phosphorus pentoxide (P₂O₅), lithium oxide (Li₂O), sodium oxide(Na₂O), barium oxide (BaO), calcium oxide (CaO), or magnesium oxide(MgO). Examples of the metal salt may include sulfates such as lithiumsulfate (Li₂SO₄), sodium sulfate (Na₂SO₄), calcium sulfate (CaSO₄),magnesium sulfate (MgSO₄), cobalt sulfate (CoSO₄), gallium sulfate(Ga₂(SO₄)₃), titanium sulfate (Ti(SO₄)₂) or nickel sulfate (NiSO₄),metal halides such as calcium chloride (CaCl₂), magnesium chloride(MgCl₂), strontium chloride (SrCl₂), yttrium chloride (YCl₃), copperchloride (CuCl₂), cesium fluoride (CsF), tantalum fluoride (TaF₅),niobium fluoride (NbF₅), lithium bromide (LiBr), calcium bromide(CaBr₂), cesium bromide (CeBr₃), selenium bromide (SeBr₄), vanadiumbromide (VBr₃), magnesium bromide (MgBr₂), barium iodide (BaI₂) ormagnesium iodide (MgI₂), metal chlorates such as barium perchlorate(Ba(ClO₄)₂) or magnesium perchlorate (Mg(ClO₄)₂), and the like, but themetal salt is not limited thereto.

In the present application, the moisture absorbent such as the metaloxide may be appropriately processed and mixed with the composition. Forexample, according to a type of the organic electronic device to whichthe encapsulant film may be applied, the encapsulant film may be a thinfilm having a thickness of 30 μm or less. In this case, a grindingprocess of the moisture absorbent may be necessary. In order to grindthe moisture absorbent, a process such as three-roll milling, beadmilling, ball milling, and the like may be used. Also, when theencapsulant film of the present application is used in a top emissiontype organic electronic device, and the like, transmittance of theencapsulant film itself is very important, and thereby a size of themoisture absorbent needs to be reduced. Therefore, the grinding processmay be necessary for such a purpose.

A water barrier layer of the encapsulant film of the present applicationmay include the moisture absorbent of 1 part by weight to 200 parts byweight, and preferably, 5 parts by weight to 100 parts by weight, withrespect to 100 parts by weight of the base resin. By controlling themoisture absorbent to have a content of 5 parts by weight or more, theencapsulant film may exhibit an excellent water and moisture barrierproperty. In addition, by controlling the moisture absorbent to have acontent of 100 parts by weight or less, the encapsulation structure ofthe thin film may be formed and the excellent water barrier property maybe exhibited. Unless otherwise defined in this specification, the unit“parts by weight” refers to a weight ratio between components.

In an embodiment, when the encapsulant film of the present applicationis a multi-layer film including a first layer that comes in contact withthe organic electronic element and a second layer that does not come incontact with the organic electronic device, the first layer may include0 to 20% of the moisture absorbent with respect to a mass of the totalmoisture absorbent in the film, and the second layer may include 80 to100% of the moisture absorbent with respect to a mass of the totalmoisture absorbent in the film.

That is, with respect to the mass of the total moisture absorbent in theencapsulant film, 0 to 20%, 0 to 18%, 0 to 16%, 0 to 14%, 0 to 12%, 0 to10%, 0 to 8%, 0 to 6%, 0 to 4%, or 0 to 2% of the moisture absorbent maybe included in the first layer. Also, 80 to 100%, 82 to 100%, 84 to100%, 86 to 100%, 88 to 100%, 90 to 100%, 92 to 100%, 94 to 100%, 96 to100%, or 98 to 100% of the moisture absorbent may be included in thesecond layer. When a content of the moisture absorbent in the firstlayer that is closer to the organic electronic device exceeds 20%, themoisture absorbent may press the organic electronic device together witha foreign material and cause physical damage, and a large amount ofionic materials may be discharged after reacting with water and causechemical damage of a cathode or an inorganic protective film.

Also, in an example, when the encapsulant film of the presentapplication has a multi-layer structure, the first layer may include themoisture absorbent at 0 parts by weight to 10 parts by weight, withrespect to 100 parts by weight of the base resin. When the moistureabsorbent is included at 0 parts by weight, the first layer has nomoisture absorbent and only the second layer has the moisture absorbent.By controlling the moisture absorbent to have a content of 10 parts byweight or less with respect to 100 parts by weight of the base resin,the water barrier property may be maximized and the physical andchemical damage of the organic electronic device due to the moistureabsorbent may be minimized.

In an example, the moisture absorbent may be in a uniformly dispersedstate in the base resin or in the film. Here, the uniformly dispersedstate may refer to a state in which the moisture absorbent has the samedensity or substantially the same density in any part of the base resinor a matrix of the film.

The moisture absorbent may be controlled to have an appropriate sizedepending on usage purposes of the film. In an example, the moistureabsorbent may be controlled to have an average particle diameter of 100to 15000 nm. The moisture absorbent having a size in the above range iseasy to store since a reaction rate with water is not too fast, anelement to be encapsulated is not harmed, and water may be effectivelyremoved.

In detailed embodiments of the present application, the encapsulant filmmay further include a tackifier according to a type of the base resin.For example, when the above-described base resin is the thermoplasticelastomer base resin, the encapsulant film may further include thetackifier. As the tackifier, for example, a hydrogenated petroleum resinobtained by hydrogenating a petroleum resin may be used. Thehydrogenated petroleum resin may be partially or entirely hydrogenated,or may be a mixture thereof. As the tackifier, a tackifier having goodcompatibility with components constituting the encapsulant film and anexcellent water barrier property may be selected. Specific examples ofthe hydrogenated petroleum resin may include a hydrogenatedterpene-based resin, a hydrogenated ester-based resin, a hydrogenateddicyclopentadiene-based resin, and the like. The tackifier may have aweight-average molecular weight of about 200 to 5,000. A content of thetackifier may be appropriately adjusted as necessary. For example, thetackifier may be included in a ratio of 5 parts by weight to 100 partsby weight with respect to 100 parts by weight of the base resin.

In addition to the above-described components, various additives may beincluded in the encapsulant film according to a usage of the film and amanufacturing process of the film. For example, when the base resin isthe thermoplastic elastomer base resin, a crosslinking material may befurther included in the encapsulant film in consideration of durabilityand processability. Here, the crosslinking material may refer to amaterial having a thermally cross-linkable functional group and/oractive energy ray cross-linkable functional group that is separatelyincluded in addition to the components constituting the encapsulantfilm. Also, a content of the crosslinking material included in theencapsulant film may be adjusted according to a desired physicalproperty of the film.

In a specific example of the present application, the encapsulant filmmay further include a curing agent according to a type of the baseresin. For example, a curing agent that may form a crosslinkingstructure and the like by reacting with the above-described base resin,or an initiator that may initiate a curing reaction of the resin may befurther included.

A type of the curing agent may be appropriately selected and usedaccording to the base resin or a type of the functional group includedin the resin.

In an example, when the base resin is the epoxy resin, curing agents ofthe epoxy resin known in the related art, for example, an amine curingagent, an imidazole curing agent, a phenol curing agent, a phosphoruscuring agent, an anhydride curing agent, or mixtures thereof may be usedas the curing agent, but the curing agent is not limited thereto.

In an example, as the curing agent, an imidazole compound that is in asolid state at room temperature and has a melting point or decompositiontemperature of 80° C. or more may be used. Examples of such a compoundmay include 2-methylimidazole, 2-heptadecylimidazole, 2-phenylimidazole,2-phenyl-4-methylimidazole, or 1-cyanoethyl-2-phenylimidazole, but thecompound is not limited thereto.

A content of the curing agent may be selected according to aconfiguration of the composition, for example, a type or a ratio of thebase resin. For example, the curing agent may be included in an amountof 1 part by weight to 20 parts by weight, 1 part by weight to 10 partsby weight or 1 part by weight to 5 parts by weight with respect to 100parts by weight of the base resin. However, the weight ratio may bechanged according to the base resin, a type and a ratio of thefunctional group of the resin, a crosslinking density to be implemented,and the like.

When the base resin is a resin that may be cured by irradiation ofactive energy rays, as the initiator, for example, a cationicphotopolymerization initiator may be used.

As the cationic photopolymerization initiator, an onium-salt-based ororganometallic-salt-based ionized cationic initiator, anorganic-silane-based or latent-sulfonic-acid-based initiator or anonionized cationic photopolymerization initiator may be used. As theonium-salt-based initiator, a diaryliodonium salt, a triarylsulfoniumsalt, an aryldiazonium salt, and the like may be exemplified. As theorganometallic-salt-based initiator, an iron arene and the like may beexemplified. As the organic-silane-based initiator, an o-nitro benzyltriarylsilyl ether, a triaryl silyl peroxide, an acyl silane, and thelike may be exemplified. As the latent-sulfonic-acid-based initiator, anα-sulfonyloxy ketone, an α-hydroxymethyl benzoin sulfonate, and the likemay be exemplified, but the initiator is not limited thereto.

In an example, as the cationic initiator, the ionized cationicphotopolymerization initiator may be used.

Also, when the base resin is a resin that may be cured by irradiation ofactive energy rays, as the initiator, for example, a radical initiatormay be used.

The radical initiator may be a photoinitiator or a thermal initiator. Aspecific type of the photoinitiator may be appropriately selected inconsideration of a cure rate, possibility of yellowing, and the like.For example, a benzoin-based, hydroxy-ketone-based, amino-ketone-based,or phosphine-oxide-based photoinitiator may be used. Specifically,benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropylether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone,dimethylamino acetophenone, 2,2-dimethoxy-2-phenyl-acetophenone,2,2-diethoxy-2-phenylacetophenone,2-hydroxy-2-methyl-1-phenylpropan-1-one,1-hydroxycyclohexylphenylketone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one,4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone,p-phenyl benzophenone, 4,4′-diethylamino-benzophenone,dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone,2-t-butylanthraquinone, 2-amino anthraquinone, 2-methylthioxanthone,2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone,2,4-diethylthioxanthone, benzyldimethylketal, acetophenonedimethylketal,p-dimethylaminobenzoateester,oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone],2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the like may beused.

A content of the initiator may be changed according to the base resin, atype and a ratio of the functional group of the resin, a crosslinkingdensity to be implemented, and the like, as in the curing agent. Forexample, the initiator may be mixed in a ratio of 0.01 parts by weightto 10 parts by weight or 0.1 parts by weight to 3 parts by weight withrespect to 100 parts by weight of the base resin.

In addition to the above-described components, various materials may beincluded in the encapsulant film according to a usage of the film and amanufacturing process of the film. For example, when the encapsulantfilm is molded in the form of a film or a sheet, the binder resin may beincluded in consideration of moldability, and the like.

In a specific example of the present application, the encapsulant filmmay include a filler, preferably an inorganic filler. The filler maysuppress penetration of water or moisture by making a moving path ofwater or moisture penetrating into an encapsulation structure longer,and may maximize a barrier property against water and moisture by aninteraction with the base resin, the moisture absorbent, and the like. Adetailed type of the filler that may be used in the present applicationis not specifically limited. For example, clay, talc, acicular silica,and mixtures thereof may be used.

Also, in the present application, in order to increase efficiency ofbinding with the filler and the organic binder, a product of which asurface is treated with an organic material may be used as the filler,or a coupling agent may be additionally added thereto.

The encapsulant film of the present application may include a filler inan amount of 1 part by weight to 50 parts by weight, and preferably 1part by weight to 20 parts by weight with respect to 100 parts by weightof the base resin. By controlling a content of the filler to be 1 partby weight or more, it is possible to provide a cured product having anexcellent water or moisture barrier property and mechanical property.Also, in the present application, by controlling a content of the fillerto be 20 parts by weight or less, it is possible to manufacture a typeof a film, and it is also possible to provide an encapsulation structureexhibiting an excellent water barrier property even when the encapsulantfilm is formed as a thin film.

The encapsulant film of the present application may have variousstructures and may be made of, for example, a single layer, or multiplelayers as described above. When the encapsulant film has a two-layerstructure, each layer may have the same or different components.

The encapsulant film may further include, for example, a substrate. Thesubstrate may be disposed in, for example, either or both surfaces ofthe film. The substrate may be, for example, a release-treatedsubstrate. Substrates used in the related art may be used withoutlimitation.

The encapsulant film may be applied to encapsulate and protect varioussubjects. In particular, the film may be effective in protecting asubject including an element that is sensitive to external factors, forexample, water or moisture. Examples of the subject to which theencapsulant film may be applied may include a photovoltaic device, arectifier, a transmitter, an organic electronic device such as anorganic light emitting diode (OLED) and the like; a solar cell; arechargeable battery, and the like, but the subject is not limitedthereto.

The encapsulant film of the present application may be applied toencapsulate an electronic device. An electronic device including anupper substrate; a lower substrate; and an encapsulant film having afilm encapsulating an element between the upper substrate and the lowersubstrate may be exemplified. In the above description, the term“element” may refer to any component of the electronic device. Arepresentative example of the element that may be protected by the filmas described above may include an organic electronic element such as anorganic light emitting element and the like, but the element is notlimited thereto.

In an example, the film includes the above-described moisture absorbent,and may be an encapsulant film that is evaluated as having highreliability through a haze measurement.

In the electronic device, the upper substrate and the lower substratemay be disposed to face each other. Also, the element is formed in asurface of the lower substrate, and the surface of the lower substratemay be a surface facing the upper substrate. The film is placed betweenthe upper and lower substrates, and the film may substantially cover anentire surface of the element. Also, when the film has a multi-layerstructure, a layer containing less moisture absorbent may be attachedcloser to the element, as described above. Therefore, it is possible toprovide an electronic device having excellent interfacial adhesionbetween the encapsulant film and the element or the lower substrate.

In an example, the electronic device may be the organic electronicdevice. The encapsulant film may exhibit an excellent water barrierproperty and optical property in the organic electronic device, and mayefficiently fix and support the upper substrate and the lower substrate.Also, for example, when the moisture absorbent is manufactured in anano-scale size and is uniformly dispersed in the resin, the encapsulantfilm may exhibit excellent transparency, and the stable encapsulant filmmay be formed regardless of a type of the organic electronic device suchas top emission or bottom emission.

The organic electronic device may have a general configuration known inthe related art except that the encapsulant film is formed of theabove-described film. For example, as the lower and/or upper substrate,glass, a metal, a polymer film, and the like, which are generally usedin the related art, may be used. Also, the organic electronic elementmay include, for example, a pair of electrodes, and a layer of anorganic material formed between the pair of electrodes. Here, either ofthe pair of electrodes may be formed as a transparent electrode. Also,the layer of the organic material may include, for example, a holetransport layer, a light emitting layer, and an electron transportlayer.

In the above description, when the film is applied to the element, thefilm is laminated in contact with the element. For example, the film maybe applied such that the film covers an entire surface of the element.

Also, lamination of the film in contact with the element may include,for example, a process in which the film comes in contact with theelement, and the film is heated to have fluidity and is compressed ontothe element. Therefore, even in an electronic device having a largearea, it is possible to provide an electronic device that has noperformance decrease due to bubbles and the like.

Also, in order to prevent bubbles and the like from being generatedbetween the element and the film, the compression may be performed usinga vacuum press and the like.

Also, after the film is laminated in contact with the element, the filmmay be cured. For example, a curing process may be performed in anappropriate heating chamber or ultraviolet chamber according to a curingmethod of the curable resin. Heating conditions or irradiatingconditions of active energy rays may be appropriately selected inconsideration of stability of the electronic device, curing property ofthe curable resin composition, and the like.

Advantageous Effects

The present application may provide a film that may be provided for anevaluation method in which reliability of an encapsulant film is simplyand easily evaluated only by measuring a haze immediately before theencapsulant film is used, a failure of a product is determined andreliability may be predicted.

DESCRIPTION OF DRAWINGS

FIG. 1 is a graph showing a relation between a haze and a content of amoisture absorbent;

FIG. 2 is a graph showing a relation between a haze and a waterpenetration distance which are measured after a test specimen made usinga film of the present application is maintained under conditions of atemperature of 85° C. and a relative humidity of 85% for 100 hours;

FIG. 3 is a graph showing a relation between a haze and a waterpenetration distance which are measured after a test specimen made usinga film of the present application is maintained under conditions of atemperature of 85° C. and a relative humidity of 85% for 300 hours;

FIG. 4 is a graph showing a relation between a haze and a waterpenetration distance which are measured after a test specimen made usinga film of the present application is maintained under conditions of atemperature of 85° C. and a relative humidity of 85% for 500 hours;

FIG. 5 is a graph showing a relation between a haze and a waterpenetration distance which are measured after a test specimen made usinga film of the present application is maintained under conditions of atemperature of 85° C. and a relative humidity of 85% for 1000 hours; and

FIG. 6 is a diagram schematically illustrating an exemplary reliablelifespan measurement device of the present application.

MODES OF THE INVENTION

Hereinafter, while the present application will be described in detailwith reference to Examples and Comparative Examples, the scope of thepresent application is not limited to the following Examples.

EXAMPLE 1 Manufacturing of Pressure-sensitive Adhesive Film

(1) Preparation of a Solution for Forming an Encapsulant Film

100 g of calcined dolomite having an average particle diameter of 5 μmwas input as a moisture absorbent, MEK having a solid concentration of50 wt % was input as a solvent, and a ball milling operation wasperformed to prepare a moisture absorbent solution. 200 g of asilane-modified epoxy resin (KSR-177, Kukdo Chemical Co., Ltd) and 150 gof a phenoxy resin (YP-50, Dong Do Tech Co., Ltd) were input in areactor at room temperature and diluted with methylethylketone. 4 g ofimidazole (Shikoku Chemicals Corp.) serving as a curing agent was inputto the homogenized solution and then high-speed stirring was performedfor one hour to prepare a water barrier layer solution. The moistureabsorbent solution prepared in advance was input to the solution suchthat a content of the calcined dolomite was 10 parts by weight withrespect to 100 parts by weight of a base resin of the encapsulant film,and mixed to prepare an encapsulant film-forming solution. In this case,a refractive index of the used epoxy-based base resin after curing was1.52 and a refractive index of the calcined dolomite was 1.8, which weremeasured by an Abbe refractometer. Due to a hydration reaction when thecalcined dolomite was reacting with water, the refractive index changedto 1.57 and became similar to the refractive index of the base resin.

(2) Manufacturing of Film

The solution for forming an encapsulant film prepared as above wasapplied onto a release surface of a release PET and dried for 10 minutesat 110° C. An encapsulant film having a thickness of 40 μm was formed,and then was placed and stored in a water-resistant sealed envelope suchthat it was not exposed to conditions of a relative humidity of 50% at25° C.

EXAMPLE 2

An encapsulant film was manufactured by the same method as in Example 1except that the moisture absorbent was input to have a content of 20parts by weight with respect to 100 parts by weight of the base resin.

EXAMPLE 3

An encapsulant film was manufactured by the same method as in Example 1except that the moisture absorbent was input to have a content of 30parts by weight with respect to 100 parts by weight of the base resin.

EXAMPLE 4

An encapsulant film was manufactured by the same method as in Example 1except that the moisture absorbent was input to have a content of 50parts by weigh with respect to 100 parts by weight of the base resin.

EXAMPLE 5

An encapsulant film was manufactured by the same method as in Example 2except that a moisture absorbent having an average particle diameter of100 nm was input.

EXAMPLE 6

An encapsulant film was manufactured by the same method as in Example 1except that the manufactured film was exposed to conditions of arelative humidity of 50% at 25° C. for 3 hours and then was placed andstored in a water resistant sealed film.

EXAMPLE 7

An encapsulant film was manufactured by the same method as in Example 1except that the manufactured film was exposed to conditions of arelative humidity of 50% at 25° C. for 5 hours and then was placed andstored in a water resistant sealed film.

COMPARATIVE EXAMPLE 1

An encapsulant film was manufactured by the same method as in Example 1except that the manufactured film was exposed to conditions of arelative humidity of 50% at 25° C. for 10 hours and then was placed andstored in a water resistant sealed film.

COMPARATIVE EXAMPLE 2

An encapsulant film was manufactured by the same method as in Example 1except that the moisture absorbent was input to have a content of 5parts by weight with respect to 100 parts by weight of the base resin.

COMPARATIVE EXAMPLE 3

An encapsulant film was manufactured by the same method as in Example 1except that a moisture absorbent having an average particle diameter of100 nm was input.

In Examples and Comparative Examples, physical properties were evaluatedby the following methods, and Tables 1 and 2 show results thereof.

1. Measurement of Viscosity

While a temperature was increased from 25° C. to 130° C., viscosity ofthe films manufactured in Examples was measured using an advancedrheometric expansion system (ARES) under conditions of a frequency of 1Hz and a strain of 5%.

2. Measurement of Haze

In order to measure a haze of the films manufactured in Examples andComparative Examples, separate specimens was prepared. Since the hazechanges depending on a thickness, all specimen films were manufacturedto have the same thickness of 40 μm and evaluation was performed. In acurable product, when a curing agent is dispersed in the form of apowder, light is scattered due to the curing agent. In order to removesuch an influence, an adhesive film was cured on a release film, thecuring agent was entirely melted, and then a haze having only aninfluence of the moisture absorbent was measured. On the other hand,when a non-curable film was used, the haze was directly evaluated. As ahaze meter, NDH-5000 (Nippon Denshoku Industries Co., Ltd.) was used fora measurement, and a measurement specification was JIS K7105. A hazevalue was measured after an exposure time had elapsed under conditionsof a relative humidity of 50% at 25° C. of the following Table 1 from atime point at which the manufactured specimen was taken out of awater-resistant sealed envelope.

Meanwhile, the haze values of the specimens of Examples 1 to 7 andComparative Examples 1 to 3 were measured while changing a content and aparticle diameter of the moisture absorbent and maintaining exposureconditions of a relative humidity of 50% at 25° C. Table 1 shows theresults. In order to compare haze values when the moisture absorbenthaving the same particle diameter and the same content is included, fourseparate specimens were manufactured in addition to those of Examples 1to 7 and Comparative Examples 1 to 3, and the haze values of thespecimens were measured by the above method. Table 2 shows the results.

3. Determination of Damage of Organic Electronic Device

An organic light-emitting panel having a bezel of 6 mm was manufacturedusing the adhesive film in Examples 1 to 7 and Comparative Examples 1 to3 and left in a constant temperature and humidity chamber underconditions of a temperature of 85° C. and a relative humidity of 85% for1000 hours, and then occurrence of dark spots was observed using anoptical microscope. Table 1 shows the results.

4. Measurement of Water Penetration Distance

The film having a thickness of 40 μm manufactured in Example was cut toa size of 40 mm×40 mm, placed at a center between two plate glasseshaving sizes of 1 mm×50 mm×50 mm, vacuum thermo-compressed, and, when itwas a curable adhesive film, cured. The manufactured adhesive film wasmaintained under conditions of a temperature of 85° C. and a relativehumidity of 85% for 0 hours to 1200 hours, and a length to which waterpenetrated from an outermost edge of the adhesive film toward a centerof the film and transparency occurred was measured using an opticalmicroscope.

Meanwhile, the water penetration distances of the specimens of Examples1 to 7 and Comparative Examples 1 to 3 were measured while changing acontent and a particle diameter of the moisture absorbent. Table 1 showsthe results. Four separate specimens including the moisture absorbenthaving the same particle diameter and the same content were manufacturedand exposed to conditions of a relative humidity of 50% at 25° C. for 0hours, 3 hours, 6 hours, and 16 hours, respectively. Then, when 73hours, 242 hours, 315 hours, 404 hours, 574 hours, 759 hours, 877 hours,978 hours, and 1118 hours had elapsed under conditions of a temperatureof 85° C. and a relative humidity of 85%, the water penetrationdistances of the specimens were measured by the above method.

TABLE 1 Com- Com- Com- parative parative parative Example ExampleExample Example Example Example Example Example Example Example 1 2 3 45 6 7 1 2 3 Content of 10 20 30 50 20 10 10 10 5 10 moisture absorbent(wt %) Average particle 5 μm 5 μm 5 μm 5 μm 100 nm 5 μm 5 μm 5 μm 5 μm100 nm diameter of moisture absorbent Exposure time of 0 0 0 0 0 3 5 100 0 film (relative humidity of 50% at 25° C.) Haze (%) 50 70 80 88 30 4743 29 25 20 Viscosity (pa · s) 1.6 × 10⁸ 1.2 × 10⁸ 0.9 × 10⁸ 0.7 × 10⁸2.3× 10⁸ 1.6 × 10⁸ 1.6 × 10⁸ 1.6 × 10⁸ 1.1 × 10⁸ 1.7 × 10⁸ Occurrence ofx x x x x x x ∘ ∘ ∘ dark spots Water penetration 4 3.4 2.8 2.1 2.5 4.24.5 5 6.2 Im- on distance (mm) after being left at 85° C. and RH of 85%for 300 hrs

TABLE 2 Exposure time (hr) in conditions of relative Elapsed time underconditions of temperature of 85° C. humidity of and relative humidity of85% (hr) 50% at room 73 242 315 404 574 759 877 978 1118 Hazetemperature Water penetration distance (mm) 75.8 0 1.39 2.54 2.92 3.283.95 4.69 4.95 5.23 5.68 73.8 3 1.43 2.69 3.10 3.49 4.11 4.89 5.19 5.485.89 69.1 6 1.59 2.92 3.33 3.75 4.51 5.28 5.64 6.06 6.5 45.2 16 2.5 4.85.40 6.30 7.60 8.70 9.40 10.1 10.9

As shown in Table 1, it can be seen that the haze value of theencapsulant film may variously change according to parameters such as acontent, an average particle diameter, etc. of the moisture absorbent.When the same moisture absorbent is used, if the haze value increases,the water penetration distance decreases and no dark spots occur.Accordingly, it may be determined that the organic electronic device hasno damage. Also, as in Example 1 and Comparative Example 1, even whenthe film including the moisture absorbent having the same particlediameter and content is used, water does not pass through a bezel of 6mm in a film having a high haze value. Accordingly, a relation betweenthe water penetration distance and the haze can be confirmed.

Meanwhile, as can be seen from the result of Table 2, in the encapsulantfilm having the same moisture absorbent, it may be seen that the hazevalue decreases as the exposure time in conditions of a relativehumidity of 50% at 25° C. increases before the film is applied to thepanel, and the water barrier property decreases as the haze valuedecreases.

REFERENCE NUMERALS

-   10: measurement device-   11: light source-   12: integrating sphere-   13: evaluation unit-   a: sample film

The invention claimed is:
 1. A method of evaluating a reliable lifespan of a film, comprising measuring a haze of a film including a base resin and a moisture absorbent within one hour from a time point at which the film is taken out of a water-resistant sealed envelope under conditions of a relative humidity of 50% at 25° C. and evaluating a reliable lifespan of the film using the measured haze value, wherein the haze value satisfies the following General Equation 1: $\begin{matrix} {{Hz} = {{- m}\;{\mathbb{e}}^{{- \phi}\;{{hr}{({{n_{g}/n} - 1})}}^{2}}}} & \left\lbrack {{General}\mspace{14mu}{Equation}\mspace{14mu} 1} \right\rbrack \end{matrix}$ where, in General Equation 1, Hz represents a haze value (%) of the film that is measured using a haze meter within one hour from a time point at which the film is taken out of the water-resistant sealed envelope under conditions of a relative humidity of 50% at 25° C., m represents a value greater than 0, Φ represents a content of the moisture absorbent with respect to the base resin, h represents a thickness of the film, r represents an average particle diameter of the moisture absorbent, n_(g) represents a refractive index of the moisture absorbent, and n represents a refractive index of the base resin, wherein the reliable lifespan of the film is evaluated as being longer when the measured haze value of the film is higher, and wherein the haze value of the film decreases due to a change in a refractive index of the moisture absorbent caused by the hydration reaction of the moisture absorbent with water.
 2. The method of claim 1, wherein the haze values of two or more films are compared and evaluated.
 3. The method of claim 2, wherein haze values of films including the moisture absorbent having the same size and the same type measured under the same conditions are compared.
 4. The method of claim 1, wherein the haze values of two or more films are compared and evaluated.
 5. The method of claim 4, wherein haze values of films including the moisture absorbent having the same size and the same type measured under the same conditions are compared.
 6. The method of claim 1, wherein the haze values of two or more films and water penetration distances of the films measured after films having the haze values are laminated between two glass substrates and maintained under conditions of a temperature of 85° C. and a relative humidity of 85% for 0 to 1500 hours are compared and evaluated.
 7. The method of claim 6, wherein the water penetration distances measured under conditions of maintaining a temperature of 85° C. and a relative humidity of 85% for the same time are compared.
 8. A method of evaluating a reliable lifespan of a film, comprising measuring a haze of a film including a base resin and a moisture absorbent within one hour from a time point at which the film is taken out of a water-resistant sealed envelope under conditions of a relative humidity of 50% at 25° C. and evaluating a reliable lifespan of the film using the measured haze value, wherein the film satisfies the following General Equation 2: D=k/Hz  [General Equation 2] where, in General Equation 2, Hz represents a haze value (%) of the film that is measured using a haze meter within one hour from a time point at which the film is taken out of the water-resistant sealed envelope under conditions of a relative humidity of 50% at 25° C., D represents a water penetration distance (mm) of the film that is measured after the film of which a haze is measured is laminated between two glass substrates and maintained under conditions of a temperature of 85° C. and a relative humidity of 85% for 0 to 1500 hours, and k is a value equal to or greater than one, wherein the reliable lifespan of the film is evaluated as being longer when the measured haze value of the film is higher, and wherein the haze value of the film decreases due to a change in a refractive index of the moisture absorbent caused by the hydration reaction of the moisture absorbent with water.
 9. The method of claim 8, wherein the haze values of two or more films and water penetration distances of the films measured after films having the haze values are laminated between two glass substrates and maintained under conditions of a temperature of 85° C. and a relative humidity of 85% for 0 to 1500 hours are compared and evaluated.
 10. The method of claim 9, wherein the water penetration distances measured under conditions of maintaining a temperature of 85° C. and a relative humidity of 85% for the same time are compared.
 11. A device for measuring reliability of a film including a base resin and a moisture absorbent, comprising: a light source configured to irradiate light to a sample film; an integrating sphere configured to detect light penetrating the sample film and measure a haze; and a measuring unit configured to measure reliability of the film using a haze value measured by the integrating sphere, wherein the measuring unit includes: an input unit configured to receive the haze value of the film measured by the integrating sphere; an evaluation unit configured to evaluate reliability of the film based on the received haze value; and a display unit configured to display the evaluation result, wherein the evaluation unit further includes a calculating unit configured to calculate a haze value (%) according to the following General Equation 1: $\begin{matrix} {{Hz} = {{- m}\;{\mathbb{e}}^{{- \phi}\;{{hr}{({{n_{g}/n} - 1})}}^{2}}}} & \left\lbrack {{General}\mspace{14mu}{Equation}\mspace{14mu} 1} \right\rbrack \end{matrix}$ where, in General Equation 1, Hz represents the haze value (%) of the film that is measured using a haze meter within one hour from a time point at which the film is taken out of a water-resistant sealed envelope under conditions of a relative humidity of 50% at 25° C., m represents a value greater than 0, Φ represents a content of the moisture absorbent with respect to the base resin, h represents a thickness of the film, r represents an average particle diameter of the moisture absorbent, n_(g) represents a refractive index of the moisture absorbent, and n represents a refractive index of the base resin, wherein, in the measuring unit, a reliable lifespan of the film is evaluated as being longer when the measured haze value of the film is higher, and wherein the haze value of the film decreases due to a change in a refractive index of the moisture absorbent caused by the hydration reaction of the moisture absorbent with water.
 12. The device of claim 11, wherein at least one value selected from the group consisting of a content of the moisture absorbent in the sample film, an average particle diameter of the moisture absorbent, a refractive index of the moisture absorbent, a thickness of the sample film, and a refractive index of the base resin in the sample film is further input to the input unit. 